This invention relates to a convertible rail-highway car moving vehicle which is provided with wheels so that it can operate over trackless surfaces as well as on tracks. More particularly, the invention is concerned with such a vehicle which can operate in relatively small spaces, in comparison with conventional shunting (switching) locomotives.
The word railway car moving vehicle is, in this patent application, understood to mean a small locomotive which is to move on rails, pulling and pushing cars; in other words, performs shunting work, and in particular in very cramped locations. The term shunting locomotive is not used to describe the vehicle because the term already has a fully established meaning implying that the locomotive runs on rails alone. In contrast, the car moving vehicle which is the subject of the present application performs the work of a light-weight locomotive on rails, but it is also able to shift from the tracks, to move in the shunting yard from one track over to another and to move in between cars on the track, to travel about the yard, over the terrain, on roads and the like.
Various types of car moving vehicles, capable of moving both on tracks and on rubber wheels, are known in the prior art. They may be classified by three categories:
1. Those car moving vehicles, modified in the first place from automobiles or from small tractors, with traction provided by rubber wheels. Such vehicles are provided with conventional rubber tires mounted with a lateral spacing equalling the gauge. It is thus understood that a car moving vehicle of this type moves on rails using the wheels, these rubber wheels supplying traction for the train. To ensure that the rubber wheels are held on the rails, small flanged wheels have been provided in front and in the rear of such a car moving vehicle, which take up part of the weight of the car moving vehicle and thereby keep the car moving vehicle on the rails; for example, 20 to 25% of the weight may be taken up. A car moving vehicle of this type develops a highly unsatisfactory tractive effort in rainy weather, and the tractive effort is virtually nil while it is snowing, or in snow-covered terrain. A car moving vehicle of this type in fact involves danger to its user, because it loses much of its tractive and braking effects in snow. PA0 2. The second category of car moving vehicles consists of those in which the flanged wheels and rubber wheels are mutually parallel and the entire vehicle is raised by means of a hydraulic jack and turned through 90.degree.. The raising operation is slow and it is not possible to lift the car moving vehicle, if of somewhat substantial weight, at all everywhere on the line. PA0 3. The third category consists of those car moving vehicles wherein the rubber tired wheels are disposed at right angles to the rails and to the flanged wheels and the rubber wheels are lowered for the duration of travelling on the road. In this instance, thus, the flanged wheels are correspondingly raised up. In such case the foremost rubber wheels may be steerable and the rear wheels, traction wheels. Of course, the arrangement is also conceivable wherein all four wheels provide traction and the front wheels are still steerable. In this case a separate power transmission system is provided for the flanged wheels and for the rubber wheels, whereby this is a complicated and expensive design.
The designs described above are all highly complex, and since in the manufacturing of car moving vehicles the production series are small--only a few units at a time--their manufacturing is rather uneconomical.
The car moving vehicle of the present invention does not belong to any one of the three categories just mentioned and in fact can be considered to belong to a new category.